Objective To evaluate the diagnostic performance of the 1997 American College of Rheumatology(ACR)criteria,the 2012 Systemic Lupus International Collaborating Clinics(SLICC)criteria,and the 2019 European League Against Rheumatism(EULAR)/ACR criteria for childhood systemic lupus erythematosus(cSLE)in Southwest China.Methods A retrospective analysis was conducted with 264 cSLE patients and 237 non-cSLE patients with connective tissue disease receiving treatment at West China Second University Hospital,Sichuan University between January 2013 and December 2022.The sensitivity,specificity,positive/negative predictive values,and accuracy of the three classification criteria were compared.Stratified analyses by sex and age were performed to comprehensively assess the diagnostic performance of the three classification criteria.Furthermore,receiver operating characteristic(ROC)curve analysis was performed to determine the optimal cut-off value for maximizing the sensitivity of the EULAR/ACR-2019 criteria.Results The SLICC-2012 criteria demonstrated higher sensitivity(93.9%vs.76.5%vs.90.2%)and accuracy(95.4%vs.87.4%vs.93.8%)compared to the ACR-1997 and EULAR/ACR-2019 criteria,while the ACR-1997 criteria showed the highest specificity(99.5%).Stratified analysis revealed stable sensitivity(94%-96%)for the SLICC-2012 criteria across sex and prepubertal subgroups.Removing the entry criterion of antinuclear antibody(ANA)≥1∶80 or adjusting the total score cut-off value to≥13(original score>10)improved the sensitivity of the EULAR/ACR-2019 criteria.Conclusion The SLICC-2012 criteria exhibited optimal diagnostic performance for cSLE in Southwest China.Modifying the cut-off value and entry requirements of the EULAR/ACR-2019 criteria could enhance its applicability in pediatric populations.